Director Robert Kenner's sequel to his acclaimed documentary "Food Inc." offers a sometimes satirical tour of the doubt industry. According to the corporate spokesmen featured here, science is essentially a public relations problem.

When a firm hires propagandists to denounce peer-reviewed research, facts about climate change and the harms of tobacco, pesticides and pharmaceuticals no longer matter. Publicists are communication experts who can be much more persuasive than boring academic specialists. As Marc Morano, a frequently broadcast pseudo-pundit, puts it here, "I'm not a scientist, but I play one on TV."

Drawing on a 2010 book by Harvard professor Naomi Oreskes and California Institute of Technology professor Erik M. Conway, Kenner's film illustrates an ongoing logical con game. It shows businesses and think tanks recycling old political doctrine to fuel public controversies against scientific consensus. It suggests that the group-think turning misinformation into creed thrives because we are essentially tribal creatures. It doesn't much matter what you believe, as long as you share the group's approved ideology.

Using images from sidewalk three-card Monte games, Kenner shows how often people can be suckered for their cash. His film demonstrates that professional cons are much, much bigger.